Same but different: New insights on the correspondence between subjective affective experience and physiological responses from representational similarity analyses

Classical views suggest that experienced affect is related to a specific bodily response (Fingerprint hypothesis), whereas recent perspectives challenge this view postulating that similar affective experiences rather evoke different physiological responses. To further advance this debate in the field, we used representational similarity analysis (N= 64) to investigate the correspondence between subjective affect (arousal and valence ratings) and physiological reactions (skin conductance response [SCR], startle blink response, heart rate and corrugator activity) across various emotion induction contexts (picture viewing task, sound listening task and imagery task). Significant similarities were exclusively observed between SCR and arousal in the picture viewing task. However, none of the other physiological measures showed a significant relation with valence and arousal ratings in any of the tasks. These findings tend to support the populations hypothesis, suggesting that there is no clear match between the evoked physiological responses and the experienced subjective affect between individuals. Statement of relevanceThe subjective affective experience evoked by an event is accompanied by physiological responses. The correspondence between physiological response patterns and the experienced affect, however, is still under debate. Classical views (Fingerprint hypothesis) suggest that affect is related to a specific physiological response, whereas recent perspectives (Populations hypothesis) challenge this view, postulating rather different physiological responses. In the current study, we used representational similarity analysis (RSA) to examine the relation between affective experience, assessed using valence and arousal ratings, and the evoked physiological reactivity across three affect-inducing contexts. Results showed significant similarities exclusively between SCR and arousal in the passive picture viewing task. However, none of the other physiological measures showed a significant relation with valence and arousal ratings in any of the tasks, supporting the populations hypothesis. These findings invite to reframe the relation between physiology and affect from invariant and homogeneous to variant and context-dependent.